Mineral deposits in tonewood
Posted: Wed Oct 26, 2022 11:18 pm
I was working with an Ovangkol ukulele back and found that as I thickness sanded it, I exposed white streaks in the grain. At first I though it might be fungal, but when I contacted the supplier, he suggested it might be mineral deposits, which put me on the right track. I have never experienced this before. I tried solvent, naphtha and alcohol on it, to no avail. Thinking minerals, as in hard water, I tried vinegar, and it seemed to take some out, and as I looked further I could see the deposits were not soft like rot or fungus, but very hard. So I looked on the 'net for info on this, and quickly found a video by Robbie O'Brien.
https://www.youtube.com/watch?v=PGF0FohKcE8
I was surprised to see him using CLR - that widely advertised stuff for cleaning crusty shower heads etc. I tried it and it seems to work; I did scrub as he suggests with a fine wire brush, and will probably use a stained pore filler to make sure no white is left exposed. There were also several threads here about ten years ago, none of which mentioned CLR, but some said acetone might draw oils and pigment out of the wood, and stain the mineral residue in the grain lines. A good day when you learn something . . . Bruce W.
https://www.youtube.com/watch?v=PGF0FohKcE8
I was surprised to see him using CLR - that widely advertised stuff for cleaning crusty shower heads etc. I tried it and it seems to work; I did scrub as he suggests with a fine wire brush, and will probably use a stained pore filler to make sure no white is left exposed. There were also several threads here about ten years ago, none of which mentioned CLR, but some said acetone might draw oils and pigment out of the wood, and stain the mineral residue in the grain lines. A good day when you learn something . . . Bruce W.